I fitted one in a van I had about 5 years ago. Was a good quality one, pioneer maybe from memory. Took the time to position the arial exactly as the instructions described.
The result? RUBBISH
It was basically like listening to a skipping CD almost all of the time. If you were in London or other major city but crucially, with no tall buildings, it was just about tolerable, but eventually I just got fed up and used it as a CD player instead.
I'm sure technology has moved on since then, especially since you can spec DAB in plenty of new cars these days, but I'd seriously recommend testing them out before you buy
I have a DAB head unit, that thankfully also does normal FM, and I agree, DAB is crap! Unlike normal radio that may crackle a bit if the signal gets bad, DAB just cuts off. Can't be arsed with it, ill stick to FM and when they stop that ill use CDs.
Nuclear Engineer, but hoping to pass my exams and be legally called a Door Supervisor.